The field of the invention relates to optical devices and more particularly to the communication of information signals using optical devices.
Short electronic interconnects are often needed between semiconductor photonic devices such as lasers and photodiodes and electronic interface circuitry. This electronic circuitry could include photonic signal drivers and photonic signal receivers. This need for decreased distance between photonic devices and electrical interface circuitry increases as the signaling data rate increases.
Photonic components are often placed on simple carrier substrates to verify operation, to do burn-in, or simply to facilitate handling of that device. This photonic device and carrier substrate may then be placed on another substrate before additional packaging is completed. This packaging may add additional electrical interfaces, such as wire bonds and long non-controlled impedance wires, decreasing the electrical performance of the photonic device.
One example is an electro-optic TO can with an optical port. After placing the optical component in a can and making electrical wirebonds, further packaging must be done in the alignment to a fiber optic cable to the optical port. The additional packaging often involves placing structures around the TO can to support and align the fiber optic cable. The physical needs of the electrical connections and mechanical devices required for alignment often consume a great deal of space resulting in the introduction of significant distance between the optical device and the fiber. The physical need of the optical port also minimizes or eliminates the possibility of placing multiple optical devices on the same semiconductor substrate.
Some commonly used photonics devices (e.g., the vertical cavity surface emitting laser (VCSEL), photodiode structures, etc.) have both electrical contacts and optical ports on the same surface of the substrate. Placing optical ports and electrical contacts on a common surface particularly exacerbates packaging problems and optimization of the performance of these devices. These packaging problems are particularly exacerbated when more than one optical component is arrayed on a common substrate. Because of the importance of optical devices, a need exists for a simple yet reliable means of electrically and optically interconnecting such devices that does not rely upon trial and error.
A method and apparatus are provided for aligning a plurality of transmission paths of an array of optical devices with a plurality of optical fibers. The method includes the steps of disposing the optical array on a first side of the transparent substrate with the plurality of optical transmission paths passing directly through the substrate, disposing a signal processor on the first side of the transparent substrate adjacent the array of optical devices, disposing a set of alignment guides on a second side of the transparent substrate parallel to the plurality of transmission paths for aligning the plurality of optical fibers with the plurality of transmission paths and coupling a plurality of signals processed by the processor through the plurality of transmission paths between the optical array and plurality of optical fibers.